Six healthy sedentary women underwent a 2-stage euglycemic-hyperinsulinemic clamp before and after 10 days of endurance exercise training to determine if vigorous aerobic exercise results in an increased sensitivity to the antilipolytic effect of insulin. Subjects exercised for 1 hr/d at 70% VO2max. Whole-body lipolysis was measured before and during the clamp procedures using D5-glycerol, and regional lipolysis was assessed simultaneously using microdialysis probes positioned in abdominal and femoral subcutaneous adipose tissue. Blood flow data indicate that basal blood flow was greater in the abdominal than femoral region, that blood flow increased in both regions in response to insulin, and that this response did not appear to be affected by training. These data indicate that the antilipolytic response to insulin may be enhanced following endurance training on the whole-body level and in the abdominal, but not femoral, subcutaneous adipose tissue.